Deprecate all diagnostics methods that use strings.

pkg/front_end/lib/src/kernel_generator_impl.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Defines the front-end API for converting source code to Dart Kernel objects.
 library front_end.kernel_generator_impl;
 
 import 'dart:async' show Future;
 import 'dart:async';
 
 import 'package:kernel/kernel.dart' show Program, CanonicalName;
 
 import 'base/processed_options.dart';
 import 'fasta/dill/dill_target.dart' show DillTarget;
-import 'fasta/errors.dart' show InputError, reportCrash;
+import 'fasta/deprecated_problems.dart' show deprecated_InputError, reportCrash;
 import 'fasta/kernel/kernel_outline_shaker.dart';
 import 'fasta/kernel/kernel_target.dart' show KernelTarget;
 import 'fasta/kernel/verifier.dart';
 import 'fasta/kernel/utils.dart';
 import 'fasta/compiler_command_line.dart';
 import 'fasta/translate_uri.dart' show TranslateUri;
 
 /// Implementation for the `package:front_end/kernel_generator.dart` and
 /// `package:front_end/summary_generator.dart` APIs.
 Future<CompilerResult> generateKernel(ProcessedOptions options,
@@ skipping 112 matching lines @@
 
     if (kernelTarget.errors.isNotEmpty) {
       kernelTarget.errors.forEach(options.reportError);
       return null;
     }
 
     return new CompilerResult(
         summary: summary,
         program: program,
         deps: kernelTarget.loader.getDependencies());
-  } on InputError catch (e) {
-    options.reportError(e.format());
+  } on deprecated_InputError catch (e) {
+    options.reportError(e.deprecated_format());
     return null;
   } catch (e, t) {
     return reportCrash(e, t);
   }
 }
 
 /// Result object of [generateKernel].
 class CompilerResult {
   /// The generated summary bytes, if it was requested.
   final List<int> summary;
 
   /// The generated program, if it was requested.
   final Program program;
 
   /// Dependencies traversed by the compiler. Used only for generating
   /// dependency .GN files in the dart-sdk build system.
   /// Note this might be removed when we switch to compute depencencies without
   /// using the compiler itself.
   final List<Uri> deps;
 
   CompilerResult({this.summary, this.program, this.deps});
 }